Deadline Effects in Ultimatum Bargaining: An Experimental Study of Concession Sniping with Low or no Costs of Delay*

In this paper we report an experimental study of the ultimatum game in which subjects bargain for constant and slowly decreasing pies, over 3 and 11 rounds with either constant or alternating offers. With decreasing pies efficiency requires early agreements, whereas constant pies allow for late efficiency. Slowly decreasing pies are here captured by a 10%-decrease of total rewards from the first to the last round. While in the alternating offer bargaining mode roles are exchanged from round to round, in the constant role mode the same party is constantly proposing. Participants play all games with changing partners but keep their role as (initial) proposer or responder over the entire experiment. Our findings offer institutional advice, e.g. that conflict can be avoided by role alternation and time pressure.